Decreased functional connectivity between the amygdala and the left ventral prefrontal cortex in treatment-naive patients with major depressive disorder: a resting-state functional magnetic resonance imaging study

Background. Convergent studies provide support for abnormalities in the structure and functioning of the prefrontal cortex (PFC) and the amygdala, the key components of the neural system that subserves emotional processing in major depressive disorder (MDD). We used resting-state functional magnetic resonance imaging (fMRI) to examine potential amygdala-PFC functional connectivity abnormalities in treatment-naive subjects with MDD. Methods. Resting-state fMRI data were acquired from 28 individuals with MDD and 30 healthy control (HC) subjects. Amygdala-PFC functional connectivity was compared between the MDD and HC groups. Results. Decreased functional connectivity to the left ventral PFC (VPFC) from the left and right amygdala was observed in the MDD group, compared with the HC group (p < 0.05, corrected). Conclusions. The treatment-naive subjects with MDD showed decreased functional connectivity from the amygdala to the VPFC, especially to the left VPFC. This suggests that these connections may play an important role in the neuropathophysiology of MDD at its onset.